Living in the green zone at ‘Rock Hall’

“Rock Hall” — the nickname for John D. Rockefeller Jr. Hall at Harvard Divinity School (HDS) — looks just like what it is: a spare, elegant building in the Modernist tradition.

But its straight lines, wide windows, and understated functionality nicely conceal what it has become: one of the most energy-efficient buildings at Harvard.

Rockefeller Hall is the latest in a growing line of University-wide retrofits and new construction projects — 50 so far — designed to conform to strict standards of sustainability.

Sustainability is the idea that resources should be used intentionally in the present in order to leave enough for the future.

Rockefeller Hall first opened in 1971, based on a design by Edward Larrabee Barnes ’38. Today, after 14 months of refurbishing at a cost of $18.5 million, it is a quiet marvel of features that conserve water, heat, and electricity; that moderate sunlight; and that freshen air at twice the rate of standard buildings.

Reusing the building instead of constructing a new one preserved over 95 percent of the structure’s floors, walls, and roofing — an immense savings of what designers call “embodied energy.”

More than 95 percent of building materials were recycled, including a full operating commercial kitchen that was boxed up and shipped to the Caribbean for reuse.

The custom double-pane windows are from Germany — but about 80 percent of the building’s new materials are from local sources. (Buying local is a feature of sustainable building.)

The new elevator is driven by gears — a savings of up to 40 percent in energy, according to HDS facilities manager Roy H. Lauridsen.

New lighting controls turn off when occupants are absent, he said, and the cafeteria is fitted with CO2 sensors to manage ventilation. In the basement, an energy recovery (“enthalpy”) wheel saves energy by regulating a seasonal heat and moisture exchange between indoor and outdoor air.

A sun-bouncing white roof reduces cooling costs. Lighting is high-voltage, which requires smaller wires and less energy. And low-flow water features use 44 percent less potable water than required by code, saving 167,000 gallons a year.

Electricity, by way of purchased credits, comes from Texas wind farms (true for the whole HDS campus). And energy usage at Rockefeller Hall is low enough to knock 35 percent off greenhouse gas emissions compared to a standard building.

That’s a reduction of 135,000 pounds of CO2 emissions a year — the hallmark of a building that is “aggressively energy-efficient,” said Edward C. Forst.

He’s Harvard’s first executive vice president, appointed this summer, and oversees the University’s new Office for Sustainability. Forst — who called the project “a steadfast commitment to sustainability” — was among officials, contractors, consultants, and HDS staffers who crowded under a white tent Oct. 28 to celebrate the greening of Rockefeller Hall.

“The newly imagined building,” Kerry Maloney called it, praising the integration of the sustainable indoors with the soul-sustaining outdoor space adjacent to the building.

Maloney is HDS director of spiritual and religious life, and said the new walkways, greenery, garden, and pleasant stone labyrinth make it once again possible to commune with “the great teachers — the trees, the wind, the air, the sunlight.”

Understanding the Rockefeller Hall retrofit is only possible by looking at how the building relates to what is outside of it, said HDS director of operations Ralph DeFlorio, because the newly green common — at 35,000 square feet — makes it easier for people to meet.

The building’s energy savings are real — and already paying dividends, he said. But “when we look at a sustainability project, we also want to have a sense of community.”

In part, the long-hoped-for green space at HDS was inspired by a 1936 photograph of the campus, showing a sward of trees and grass. That was torn up after World War II for veteran student housing, and was later paved over for a car-crammed parking lot. To keep the old green vision in mind, DeFlorio taped the 1936 photo to his office door.

HDS Professor Kimberley C. Patton spoke at the October ceremony, and remembered emerging from HDS classes in the 1970s, energized by ideas — only to confront “row upon row of cars,” she said. “One missed a peaceful place to pause.”

Now, “Harvard Divinity School has a green horizon once more,” said Patton, who called open space a boon “to the mind’s highest operations.”

Getting to that renewed green horizon and a newly green Rockefeller Hall required “literally hundreds of people, whose engagement had to be coordinated,” said HDS Executive Dean Julie Bisbee, recalling a project that swarmed with architects, engineers, consultants, staffers, and trade workers.

“The most energizing aspect of this project for me was the Divinity School’s passion for doing the right thing,” said Nathan Gauthier, assistant director of the Harvard Office for Sustainability, who helped with the design phase. The result, he added, is “the most significant greenhouse gas reduction in a Harvard building to date.”

The re-design of Rockefeller Hall started in 2004. Construction began last June and wrapped up late this summer.

What were once 39 dormitory rooms on the upper three floors are now offices for HDS staffers, who moved in Aug. 1. On the first floor, there are five state-of-the-art seminar rooms, a refurbished lounge, and a sunny refractory that opened to students Sept. 15. Along one wall is a mural-like line of bright and brilliant glass paintings by Cambridge artist Linda Lichtman.

Rockefeller Hall is on its way to being certified LEED Gold. (LEED stands for Leadership in Energy and Environmental Design, an industry scheme for ranking sustainable building projects. Platinum is the highest rating, followed by Gold and Silver.)

It will be Harvard’s fourth LEED Gold building, said Gauthier. The University has finished 14 LEED projects, he said, and has 36 more in the design or construction phase.

That’s more LEED-certified real estate than any other university, said Forst last month. He added that HDS already has some sustainability firsts to its name: the first School to test green cleaning supplies, and the first to make composting mandatory.

All this, said Forst, “makes other parts of the University watch.”